Many English folks are clueless about the horn statuses of their Dexters. Many have have largely "de-horned" their Dexters for many decades, obliterating all evidence of horn status. Many have very little genetics knowledge about how horn/poll/scur genetics work, and rarely test their assumed "horned" to look for hidden poll genes.
Here is a discussion from 2011 (before testing for poll genes was available).
The post you have copied from a UK chat forum is a THEORY. . . . . which you have copied and lug around here and there to transplant as if it is reality. The truth is. . . . . . I could offer a better one based on facts rather than supposition as to horn issues in Woodmagic, and other traits. BUT . . .it would still be a theory even if based on factual what-ifs.
There were a number of Woodmagic cattle imported to Canada in the late 1970's, whose offspring and descendants filtered into the US, along with a couple AI bulls from those cows, and another AI bull directly from England.
I HAVE NOT SEEN YOU POST A SINGLE PHOTO OF A POLLED OR SCURRED ANIMAL FROM WOODMAGIC LINES IN AMERICA.
You just keep posting your own theory or the theory of others who would attempt to disparage the lifetime work and effort of Mrs. Rutherford, who almost singlehandedly saved the Dexter breed in England. Much like Grinstead, there are few animals in England without Woodmagic in their pedigree.
You should cease immediaely posting this drivel that has no scientific basis in theory or reality so Mrs. Rutherford can lie back down and stop rolling in her grave.
FURTHERMORE. . . . . .. .EVERY single time you tried to prove this "theory" of yours. .. . . including on at least one Woodmagic animal, ( Trillium Cluny) you FAILED. You cannot change the dynamics of your herd, ( descended from a documented GRADE bull by the constant insinuations you make on the herds of others with nothing but gossip and innuendo, (often of which you are the source). Dexter cattle are a HORNED breed. They always have been. They should always be. They probably will be again for the polled lines really have nothing unique to offer in the world of cattle and they cannot compete with existing polled breeds. They are doomed. Woeful will be those on the bottom of the pyramid of lies.
The British isles, including Ireland, has had a mix of horned and polled cattle for the past 1000 years or more.
The poll gene is NOT always dominant. The poll gene can hide in horned animals. When horns grow on animals with hidden poll genes, we often call those horns "scurs", but scurs can be the same as regular horns.
Large populations of "Horned" cattle will almost always have a mix of true horns and scur-horns with hidden poll genes. There will also be occasional smooth polled, or nearly smooth-polled animals born in a "horned breed.
All horned cattle have some polled ancestry, and all polled cattle have some horned ancestry.
The official Dexter breed as a true breed was established in 1890 when the Royal Dublin Society established a registry and set rules for registration.
The Irish rules allowed any cattle of any breed and background to become foundation "Dexters" if they met the breed description which said red or black only, short and thick bodies, but no mention of horns. Poll cattle were allowed and some Royal Dublin Society members, including the Harley Herd and Chantry Herd appeared to be working on poll lines.
The English copied the Irish and established their own English version of Dexters. The English added horns to their Dexter show standards in 1900, but the English didn't require horns for registration.
No Dexter registries recorded the horn statuses of Dexters until very recently.
Godstone Esmeralda, born in 1980, has a very pure old pedigree. She traces back to the 1800's Harley Poll and Chantry Poll lines of Dexters. None of her parents, nor grandparents, nor great-grandparents have records of horns, nor photos of horns.
Godstone Esmeralda also descends from Spalpeen, a 1912 polled Dexter bull with scurs.
Here is Spalpeen, great, great, great.... grandsire of Godstone Esmeralda and Saltaire Platinum:
Pure supposition from your desperation theories. You are a polled breeder and do not even recognize a horned poll versus a polled poll. that bull is apparently dehorned. They were dehorning cattle to such an extent by the late 1800s that Charles Plumb, a professor even then, wrote an article about dehorning.
quote from Wickihow article with link below;
Understand what polled cattle are. Polled cattle have absolutely no horns, nor scurs nor bare spaces where a pair of horns may have been, whatsoever. The best way to tell is if a cow, bull, steer or heifer is polled is by looking at the poll, itself located just above and between the ears. If it forms some sort of peak, then the animal is indeed polled, not horned, scurred or dehorned.
How to Identify Horned Scurred and Polled Cattle_ 6 Steps.pdf
They are describing homozygous-polled animals that are usually smooth-polled and usually have a "peaked" poll at the top of their heads, but they have excluded heterozygous-polled from their description.
Heterozygous-polled cattle can be smooth-polled or have small scurs, or have nearly complete horns. Some heterozygous-polled Dexters , especially bulls, dont have a peaked poll, but rather have a head that is very similar to a dehorned head shape. I've got a heterozygous-polled bull right now and he doesn't have a "peaked" poll.
Here is a Dexter calf tested by UC Davis as heterozygous-polled.
Heterozygous polled, one marker for the Celtic polled gene means he only carries a polled gene but the bull is clearly expressing the horned gene. Would it be possible to post his pedigree to see where the polled marker is coming from?
PUREBRED is a misnomer. That is basically THREE generations from an outcrossing and if the genetics are not diluted and especially if there is line breeding. . . .. . the CROSSBRED genetics become dominant.
The polled lines barely resemble the original Dexter. On occasion I will see a dish face or a chondro body. . .. but . .. . . over and over and over. . . . . . cattle people remark on their size and their difference.
I am going to say it once again because it is so puzzling to me that a person who brags about being a preservationist for guinea hogs, ( and being a large factor in "saving" that breed) and who breeds Icelandic sheep, would have any part in the destruction of a minor historical breed. Dexter cattle are a HORNED breed. Polled cattle are a NEW breed, developed via outcrossing and the lack of truthfulness about the origin in America nearly wiped out the horned bloodlines of this breed. That is simply a tragedy, no different than if the White Dexters were misrepresented in the same way and wiped out the traditional bloodlines. You are part of the problem not the solution and your blatherwaite theories which attempt to legitimize the tragedy are in stark opposition to your other stances.
your 99.9 that you came up with applies to genes that have been isolated ie PHA. They have not isolated a specific gene for polled that has not been done yet. The test they run is on an area of chromosome where they believe it exists. Given that it is actually very accurate but not 99.9 as you claim. I can not find a specific percentage for dexter but I did find one for jersey and the accuracy is 95% for them. We do know that is not a perfect test and we do know that the wrong results have come back on a few in the Dexter breed.
I alone have had UC Davis conduct about 100 polled tests on my Dexters. That's a pretty good sample size. 100% of mine have been accurate.
I know other folks with similar results.
Out of many thouaands of polled tests, I've heard of a tiny handful of errors.
But in the case of this black polled Dexter calf above (with scur horns) there is zero reason to suspect an error. He is polled with scur-horns just like his sire and grandmother.
By the way, I paid for a test on "Trillium Cluny" and he came back as homozygous-horned (no polled genes found). Should we doubt that test because the tests aren't 100% accurate? Maybe Trillium Cluny is polled after all?
The developer of the test may claim accuracy of the test itself, but they cannot claim accuracy as to lab results.
I was always critical of ADCA refusing to use UCD for testing (political and control reasons), and establishing cattle testing in a small private Equine research lab with no experience with cattle testing. Whereas UCD has a world-wide reputation for accuracy, the Cothran lab made many mistakes. Parentage, color, A2, polled.
You posit theories and try to portray them as defined science, when in fact the scientific community has been struggling to achieve clarity regarding polled for a long time. Over a decade ago, ADCA permitted Cochran to use their member’s samples in researching for the “polled gene”, when there was a worldwide race to find it. Dr. Schmutz in Canada researched extensively as well. Today, there is still ongoing research, and there is even less known and understood as to scurs.
There is lots of criticism of science now.....especially when political bias has reflected on scientific results, not to mention the corruption nurtured by financial or professional gain. I see your theories as being the same sort of pseudo-scientific conclusions. You present a picture and offer unsubstantiated conclusions as fact in order to bolster your political position.
PS. You know there have been Holstein polled identified in the polled lines?
The two versions of poll factors found so far (Celtic and Friesian), have been around in cattle for a long time.
In 1890, when the Irish Dexter Breed was founded, the rules allowed ANY cattle of any cross-breed and any background and ANY horn status to become foundation "Dexters". This would have allowed both Celtic poll genes and Friesian poll genes to enter the breed. Dexters started as a bit of everything.